CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   OpenFOAM Pre-Processing (http://www.cfd-online.com/Forums/openfoam-pre-processing/)
-   -   Multi-region problem using laplacianFoam (http://www.cfd-online.com/Forums/openfoam-pre-processing/125715-multi-region-problem-using-laplacianfoam.html)

Multi-region problem using laplacianFoam

Hi FOAMers!!

I'm quite new in this fascinating world (this is actually the first thread I open) and the most I have done since I started with this is to solve heat conduction problems using laplacianFoam. I have tried other solvers of the tutorials directory, mainly the ones related to heat transfer, but the problems I've had to solve until now I have solved them with laplacianFoam,

The point is that now I'm facing a heat conduction problem in a piece made of two diferent materials (with convection BC's). I don't know exactly how to implement it in OF, I've been reading lots of threads here in the forum but I still can't see it clear... I have seen there are more than one method to define the geometry: using a "*.setSet" file, naming the different blocks in the blockMeshDict file... And I don't know if there are more ways to do it. I still don't even understand clearly the way BC's are defined in a multi-region case.

But my main question is can I solve a multi-region problem with the laplacianFoam solver? If so, How can I do it?

The way I see it, the fact that a problem has multiple regions has nothing to do with the kind of solver used but a teacher of mine, who is training me with the use of OF, told me it was not possible with laplacianFoam and I had to use chtMultiRegionFoam. Besides, all threads I've read in the forum (except one of them) about multi-region problems talk about chtMultiRegionFoam so I don't know if my teacher is right or not...

Any post will be welcome and apreciated. Thanks in advance!

Could anyone, please, help me with this problem? I need some hint to solve it urgently!

 cliffdub August 22, 2014 17:44

Hi Alex,

Did you have any success on solving your multiregion Laplacian? I also would like to do this.

Thanks,

Cliff

Hi Cliff,

It's not possible to solve a multiregion problem with laplacianFoam solver. LaplacianFoam is only valid for single regions. The only way to solve that sort of problems is using chtMultiRegionFoam. There you just have to define all your solid regions in the regionProperties file down to constant folder and leave empty the fluid option in the same file.
Finally I never had to solve this kind of problem but I'm sure it has to work fine.

Hope it helped.

Alex

 cliffdub August 25, 2014 22:50

Thanks much Alex. I have it working now. I didn't leave the fluid option empty ( ).

Could you, please, post your approach, Cliff? This way you could help people (maybe me aswell) in the future.

Thanks!

Alex

 cliffdub August 27, 2014 15:29

I was able to use chtMultiRegion to solve conduction between two solids by just leaving the fluid regions empty in regionProperties, like this:

Code:

```         regions (     fluid    ()     solid    (leftSolid rightSolid) );```